High-electron-mobility transistors (HEMTs), also known as heterostructure FETs (HFETs) or modulation-doped FETs (MODFETs), are a type of field-effect transistor. Whereas a traditional n-type MOSFET includes a gate electrode arranged over a p-type doped channel region that separates n-type source/drain regions, for example, a HEMT device uses a heterojunction as the channel instead of a doped region. This heterojunction is defined by an interface at which two materials with different band gaps meet one another. III-N (tri nitride) devices are one type of HEMT where the heterojunction is made up of a Group-III material (e.g., Al, Ga, In) and a nitride (N) material. These III-N devices show very promising performance in high-power and high-frequency applications. III-N devices can be used, for example, in high power-high frequency applications such as emitters for cell phone base stations, Direct Broadcast Satellite (DBS) receivers, electronic warfare systems, etc.